[pre]
SS 1-3-2204 121-00-18.00 222.3822 89-52-10.33 5.320/6.500 'TCS1
SS 1-3-2205 121-02-27.60 222.3796 89-57-50.43 5.320/6.500 'GUT1
SS 1-3-2206 121-16-39.72 222.4394 89-56-45.65 5.320/6.500 'CB
SS 1-3-2207 121-14-04.20 222.4927 90-50-13.86 5.320/6.500 'IE-BOTTOM
SS 1-3-2208 121-29-21.12 222.4777 90-28-46.73 5.320/6.500 'IE-8" CONC SOUTH
SS 1-3-2209 123-19-27.48 6252.5905 91-15-45.68 5.320/6.500 'PNSIG
SS 1-3-2210 121-16-39.72 226.5482 89-56-26.22 5.320/6.500 'PNSIG
SS 1-3-2211 121-24-42.48 218.9872 89-55-14.96 5.320/6.500 'PNSIG
SS 1-3-2212 121-16-46.20 210.6411 89-54-32.85 5.320/6.500 'PNSIG
SS 1-3-2213 119-43-46.92 227.1393 89-50-55.82 5.320/6.500 'PNSIG1
SS 1-3-2214 122-11-18.60 157.9980 89-48-52.81 5.320/6.500 'GUT1
[/pre]
Just a string of topo shots. Then a single outlier. Spectra Precision Focus30 gun.
Topo along a road?
Maybe locked on an automobile reflector/sign?
Through foliage perhaps?
The gun was probably seeing a reflection of the prism in a car window or head light.
The guy was probably too busy putting on his make-up and wasn't paying attention.....oh wait, you meant rogue.:-P
Rogue shot
OOPs!
Maybe I did mean rouge, like a single point for a missed field goal in the CFL.
Rogue shot
Yes, that data definitely needs some polishing in one spot- but rouge ain't gonna help here 😉
The only superior evidence is that which you haven't yet found.
Some years ago I was using a Topcon 301 for cadastral work. We had a set up looking down and across a canyon. We repeatedly got an exactly 1000 meter error making that shot. Ended up radioing another crew to bring their instrument over to get the shot. That shot happened to be directly to an existing monument we had pre computed so we immediately knew it was a bad shot. One other time with the same gun we had a relatively small loop that misclosed. Re-ran it and found one shot that was exactly 1 meter different than the origin traverse.
Used the 301 for several years and only had those 2 instances of bad distances. Topcon said it was likely something random to do with 1's and 0's and binomal (sp?) nature of the internal workings.
Rogue shot
Some years back I worked for an outfit whose crews had Geodimeter 630's - the progenitor of the Trimble 5603. 6 crews, all with the same model guns and data collectors. Same glass, same tipods, same rods. One particular crew would, from time to time, have one of these wild shots in a string of topo. Never happened to anyone else.
I've had a few instances of road signs falling within the cone of EDM beam and instrument reading the reflection off the sign rather than the prism. The reflective paint apparently gives a strong enough return that it fools the gun. In one case the sign was quite some distance beyond the prism.
Just because I'm paranoid, doesn't mean they aren't out to get me.
If you subtract 6000' does that distance make sense? It looks like it would be in the ball park.
Rogue shot
I had a Spectra Precision/Geodimeter 600 series that did that as well. It took me months to get anybody to accept that there was something wrong with the gun. Finally they replaced it with another new instrument, which also had problems, which in turn got replaced with a new 5600 series instrument.
I think there were some issues with the Geodimeter/Spectra Precision/Trimble transition.
Reviewing data on board shows the same then this computer print-out?
Rogue shot
It does
[pre]
SS,OP1,FP2204,AR121.001800,ZE89.521033,SD222.382228,--TCS1
SS,OP1,FP2205,AR121.022760,ZE89.575043,SD222.379604,--GUT1
SS,OP1,FP2206,AR121.163972,ZE89.564565,SD222.439413,--CB
OF,AR121.140420,ZE89.565537,SD222.469072
OF,VD-3.450,--Elevation Offset
SS,OP1,FP2207,AR121.140420,ZE90.501386,SD222.492734,--IE-BOTTOM
OF,AR121.292112,ZE89.561974,SD222.470056
OF,VD-2.100,--Elevation Offset
SS,OP1,FP2208,AR121.292112,ZE90.284673,SD222.477725,--IE-8" CONC SOUTH
SS,OP1,FP2209,AR123.192748,ZE91.154568,SD6252.590543,--PNSIG
SS,OP1,FP2210,AR121.163972,ZE89.562622,SD226.548239,--PNSIG
SS,OP1,FP2211,AR121.244248,ZE89.551496,SD218.987182,--PNSIG
SS,OP1,FP2212,AR121.164620,ZE89.543285,SD210.641119,--PNSIG
SS,OP1,FP2213,AR119.434692,ZE89.505582,SD227.139347,--PNSIG1
SS,OP1,FP2214,AR122.111860,ZE89.485281,SD157.997976,--GUT1
[/pre]
> I've had a few instances of road signs falling within the cone of EDM beam and instrument reading the reflection off the sign rather than the prism. The reflective paint apparently gives a strong enough return that it fools the gun. In one case the sign was quite some distance beyond the prism.
I saw distance errors when measuring in these conditions. Was using a Geodimeter 4400 which had a very powerful EDM (5 miles to a single prism!) so I had to be careful and pay attention to what was beyond the prism or very near the line of sight between me and the prism.
12 or 13 years ago, I had the same problem, same gun.
We finished the job shooting every shot in both feet and meters to compare it was shooting correct.
It was always an increment of 1. 1000 meters, 100 meters, 10 meters, 1 meter, 0.1 meter, you get the picture. In feet, same thing.
It happened maybe 14 or 15 times in the course of a week.
Rogue shot
> It does
>
> [pre]
> SS,OP1,FP2204,AR121.001800,ZE89.521033,SD222.382228,--TCS1
> SS,OP1,FP2205,AR121.022760,ZE89.575043,SD222.379604,--GUT1
> SS,OP1,FP2206,AR121.163972,ZE89.564565,SD222.439413,--CB
> OF,AR121.140420,ZE89.565537,SD222.469072
> OF,VD-3.450,--Elevation Offset
> SS,OP1,FP2207,AR121.140420,ZE90.501386,SD222.492734,--IE-BOTTOM
> OF,AR121.292112,ZE89.561974,SD222.470056
> OF,VD-2.100,--Elevation Offset
> SS,OP1,FP2208,AR121.292112,ZE90.284673,SD222.477725,--IE-8" CONC SOUTH
> SS,OP1,FP2209,AR123.192748,ZE91.154568,SD6252.590543,--PNSIG
> SS,OP1,FP2210,AR121.163972,ZE89.562622,SD226.548239,--PNSIG
> SS,OP1,FP2211,AR121.244248,ZE89.551496,SD218.987182,--PNSIG
> SS,OP1,FP2212,AR121.164620,ZE89.543285,SD210.641119,--PNSIG
> SS,OP1,FP2213,AR119.434692,ZE89.505582,SD227.139347,--PNSIG1
> SS,OP1,FP2214,AR122.111860,ZE89.485281,SD157.997976,--GUT1
> [/pre]
I wonder if the combination of the offset command along with a code with empty spaces in the previous measurement could have create some kind of confusion in the program? That would be my guess.
Years ago I found Sokkia SET2 or 4's (late 80's models) occasionally adding exactly 10 meters to a slope distance. I caught the ones that happened on dense point topos like the example above :). I recall another time and instrument that during stakeout got confused by 2 pieces of glass nearly in line but hundreds of feet apart. If I recall correctly it reported a garbage distance. Let us know if you go back to the site and find something reflective in the background of that shot.
Pretty sure that I got a shot like that while using a Nikon that reflected off my vest. I was in the middle of the woods with nothing else around me for it to reflect off of. It was about a 1000 feet or so off.
Looking at the records, comparing the sequencing of other shots, to me it looks like an internal issue. 6,000+ ft is a long ways for a bad shot on an unknown reflective surface, so I am skeptical.
Maybe the field note sketch can shed some light on where that shot should have been (AR, VA, SD).